Method of making piston rings



y 1932. E. R. HELLMAN METHOD OF MAKING PISTON RINGS Original Filed July 11, 1950 ATTO EY Patented May 3, 1932 UNITED STATES PATENT OFFICE ERNEST R. EELLMAN, OF DETROIT, MICHIGAN METHOD OF MAKING PISTON RINGS Driginal application filed July 11, 1930, Serial No. 467,275. Divided and this application filed January 15, 1931. Serial No. 508,986.

This invention relates to piston rings and appears in Fig. 3. In the outer face of the more particularly to methods of making pisring there is cut an annular groove 5, ointly ton rings, this being a divisional of my pendformed in the parts 1, and having its depth ing application, Serial No. 467 275, filed July suitable to take care of surplus oil. This 11, 1930. groove, as Fig. 3 best shows, intersects the 55 An object of the invention is to produce by recesses a opening from the inner face of the an improved method a piston ring having ring and jointly formed bythe bevels 4. Each a provision for preventing oil leakage past part 1 is split, as indicated at 6, to permit a the ring and facilitating a radial flow through compression of the ring, the split ends of the the ring of such surplus oil as it encounters, two parts being at opposite sides of the ring 6.0 so that such oil may be returned to the crankwhen the latter is assembled, as Fig. 5 makes case through the usual passages opening clear. through the piston wall from the ring As the piston reciprocates, any surplus oil grooves. finding its way between the ring and cylin- 1 This and various other objects the invender wall is trapped in the grove 5 and de- 6? 'tion attains by the construction hereinafter livered through the passages 56; and openings described, and illustrated in the accompanyin the piston Wall, leading from the groove ing' drawings: 2 to the piston interior, whence it may drip Fig. 1 is a perspective View of one of a pair back to the crank-case. of duplicate members, forming the ring pro- The inwardly flaring form of the passages to duced by the improved method. 5a offers a minimum of resistance to oil flow Fig. 2 is a view illustrating a means for ing from the outer face of the ring for a formin the two )arts of the 1m roved rin iven area of 0 611111 in said face and furc: 1 l a g P s with a shallow groove in the cyl1nder-engagtlier has been found much less susceptible to ing face of the ring to trap oil. clogging by carbon deposits than passages Fig. 3 1s a cross-sectional view of the ring, of constant cross-section or flaring toward taken upon the hue 33 of F1g. 2. the outer face of the ring.

Fig. 4 is a fragmentary, elevational view In the preferred method of forming the deof a piston, sectionally showing the ring enscribed ring, there is initially formed a pair 30 gaged in a groove of said piston, and sectionof annular castings 1, each having cored in a ally showing the associated cylinder Wall. side face thereof a series of bevels 4, as best Fig. 5 a cross-sectional view of the same, appears in Fig. 1. The outer faces of said talren in part upon the line 5-5 of Fig. 4. castings and their side faces, exclusive of the Fig. 6 is a view similar to Fig. 4, but showbevels 4, are next ground smooth, and a small 5 ing an alternative ring construction. segment is then sawed or otherwise cut from Fig. 7 is another view similar to Fig. 4, and the ring, so as to permit the resulting beveled showing a further modification of the ring. end faces 6 to be brought into close proXimi- In these views, the reference character 1 ty on contraction of the ring to its working designates a pair of annular, duplicate parts diameter. The members 1 are then firmly 4a which jointly form a piston ring, said parts held, through any suitable means, in the con in use lying side by side in the usual groove tact illustrated in Fig. 2, their beveled faces 2 of a piston 3. One side face of each of said being adjacent, and by a circular saw 11 or parts formed with circumferentially other suitable tool, the shallow groove 5 is elongated bevcls 4 at regular intervals, formjointly formed in their outer faces, its depth 45 ing angles preferably approximating twenbeing such as to intersect the oil passages 5a. 5 ty-five degrees with said side faces. In the The ring is now ready for assembly, the asassombled relation of the parts 1, the bevels sembling operation consisting in establish 4 are so opposed on said parts as to converge ing the two rings side by side with their bevtoward the outer face of the ring, tending eled faces registered circumferentially. 50 to meet closely adjacent to said face, as best While it is apparent that the illustrated embodiment of my invention is well calculated to adequately fulfill the objects and advantages primarily stated, it is to be understood that the invention is susceptible to variation, modification and change within the spirit and scope of the subjoined claims.

What I claim is:

1. A method of forming piston rings consisting in initially producing in a pair of duplicate annular members similar circum ferentially spaced bevels, such as to progressively reduce the thickness of said'm'emhers toward their inner faces, splitting said I members, placing said members in juxtaposition with the bevels of one opposing those of the other, and forming jointly in the outer faces of said members a circumferential groove intersecting said bevels.

.2. A method of forming piston rings consisting in initially producing a pair of substantiallyidentical annular casting each having .cored in one of its side faces a plurality of similar circumferentially spaced bevels, such as to progressively reduce the thickness of said castings toward their inner peri- .pheries, establishing said members in coaxial juxtaposition with their beveled sides contiguous, and cutting a circumferential groove, intersecting said bevels, jointly in o the outer peripheries of said members.

3. A method-of forming piston rings con- .sisting in initially forming each of a pair of substantially identical annular members, with a plurality of circumferentially spaced channels extending between the outer and inner periphery of such member and having its walls acutely diverging from the outer to the inner periphery, establishing said members ina coaxial relation with their channeled faces contiguous, and cutting a circumferential groove, intersecting said channels, jointly in the outer peripheries of said members.

.In testimony whereofl sign this specification: 6 ERNEST R. HELLMAN. 

